A fluid controller generally includes: a body which is provided with a fluid passage; a valve element which opens and closes the fluid passage; a valve rod which moves the valve element in an opening or closing direction by ascending or descending; and an actuator for driving the valve rod; and so on.
A fluid controller actuator is configured by a biasing member for biasing the valve rod upwardly or downwardly, and a piston which moves the valve rod upwardly or downwardly.
In PTL 1, a fluid controller actuator which uses a biasing member configured by a plurality of disc-shaped diaphragm springs, is disclosed. In particular, the fluid controller actuator in PTL 1 includes: a casing which is attached above a body; a biasing member which is configured by a plurality of disc-shaped diaphragm springs having a through hole at the central portion thereof, and biases a valve rod downwardly by a lower side peripheral edge portion of the through hole; a columnar movable member which is disposed on an upper end surface of the valve rod; a spring receiver which is fitted to an outer periphery of the columnar movable member to be relatively vertically movable and receives the lower side peripheral edge portion of the through hole of the biasing member; an inner side spring presser which presses an upper side peripheral edge portion of the through hole of the biasing member downwardly; a plurality of bolts which fix the inner side spring receiver to the casing; an outer side spring presser which presses an outer peripheral edge portion of the biasing member downwardly; and an operation air introduction chamber which presses the outer side spring presser downwardly as operation air is introduced. In a state where the operation air is not introduced into the operation air introduction chamber, the biasing member is elastically deformed so that a protrusion amount with respect to a shape of protrusion which is downward in a natural state is small, and biases the valve rod downwardly and an outer side spring pressing ring upwardly, respectively. As the operation air is introduced into the operation air introduction chamber, the outer side spring presser is pressed downwardly, and the biasing member is deformed upwardly in a shape of protrusion.